Pile elevating mechanism



April 18, 1961 A. G. ROYER ETAL PILE ELEVATING MECHANISM l0 Sheets-Sheet 1 Filed June 5, 1959 6 Po YER- mmMA/vfi m rrs Arm 5Y5 April 18, 1961 A. G. ROYER ETI'AL PILE ELEVATING MECHANISM 1-0 Sheets-Sheet 2 Filed June 5, 1959 L\ N INVENTORS a, APT/4w? G-Pova? BY 5HEMAN .M Arrs I I W M7 Arrm? April 18, 1961 A. G. ROYER ETAL 2,980,422

PILE ELEVATING MECHANISM Filed June 5, 1959 10 Sheets-Sheet 3 INVENTOR-S Aer/1w? 6. Po YER PILE ELEVATING MECHANISM Filed June 5, 1959 10 Sheets-Sheet 4 INVENTORS Aer/4w? 6 R0 YER BY 5HERMHN 5. M44175 April 18, 1961 A. G. ROYER ETAL 2,980,422

FILE ELEVATING MECHANISM Filed June 5. 1959 10 Sheets-Sheet 5 INVENTORS Aer-Hue 6 Pa YER 5HEPM/7N 5. W4 rzs ATT'OFNEYS April 18, 1961 A. G. ROYER ETAL PILE ELEVATING MECHANISM l0 Sheets-Sheet 6 Filed June 5, 1959 QM wam .QQN m .l ll lmw;

A5 J Y W April 18, 1961 A. G. ROYER ETAL 2,980,422

PILE ELEVATING MECHANISM Filed June 5, 1959 10 Sheets-Sheet 7 IN VEN TOR.5 APT/ 0P 6. k0 YER BY SHEPMHN 5 Vmrrs Arr-a NE vs April 18, 1961 A. G. ROYER ETAL FILE ELEVATING MECHANISM Filed June 5, 1959 10 Sheets-Sheet 10 INVENTORS Aer/ we G- /?o YER PILE ELEVATING MECHANISM Arthur G. Royer, Cleveland Heights, and Sherman S.

Watts, Shaker Heights, Ohio, assignors to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed June 5, 1959, Ser. No. 818,313

23 Claims. (31. 21 1-62 The present invention relates to a pile elevating mechanism for elevating a sheet pile While sheets are being periodically removed from the top thereof to maintain the top of the pile at approximately a predetermed level, and, more particularly, to such a mechanism having main and auxiliary hoists so that the pile may be replenished from below without interrupting the sheet removing operation.

It is known in a continuously feeding pile elevating mechanism to provide a main pole hoist and an auxiliary pile hoist disposed above the main pile hoist and adapted to take a remnant or partially depleted pile therefrom and continue its elevation while a new pile is being brought into position on the main hoist. Such a mechanism is shown in United States Patent No. 2,701,136 to Morton Schmidt. In this type of apparatus the main pile hoist is operated to intermittenly elevate a pile of sheets thereon as the top sheets of the pile are removed and until the major portion of the pile is exhausted and a partially depleted or remnant pile remains. At this time the remnant pile is transferred from the main pile hoist to the auxiliary pile hoist, the latter then being operated to raise the pile as sheets are removed from the top of the remnant pile and while a new pile of sheets is placed on the main pile hoist. Conventionally the piles are supported on pallets with the pallets being engaged and lifted by the hoists to elevate the piles. After a new pile on a pallet has been brought into position, the new pile is elevated to a position where the top of the new pile is disposed in juxtaposition to the underside of the pallet supporting the remnant pile and the pallet supporting the remnant pile is subsequently withdrawn from below the remnant pile to deposit the remnant pile onto the top of the new pile thereby combining the piles, the main hoist then being operated to maintain the top of the combined piEe at the proper level.

In one type of known apparatus, the height of the top of the pile is gauged by pile-height gauging means which effects operation of the pile hoists to maintain, during normal operation, the top of the pile'from which sheets are being taken at a height which enables sheet separating and forwarding suckers disposed above the rear edge of the pile to function properly. As is disclosed in the application for Letters Patent Serial No. 698,430, filed November 25, 1957, by Arthur G. Royer, pallets used to support the piles on the hoists have been constructed to have a reduced thickness at the edge which is drawn atent last from under the remnant pile during the pile combining operation so that the rear edges of the new and remnant piles may be brought closer together than the thickness of the pallet before the pallet is completely withdrawn and the rear edge of the remnant pile permitted to drop onto the new pile. This prevents the rear edge of the remnant pile from dropping, at one time, the full thickness of. the pallet as the latter is withdrawn. If the rear edge dropped the full thickness of the pallet in one step, the drop would lower the top of the rear edge to a point where it would be diflicult or impossible ice for the sheet separating suckers to reach the top of the pile.

The proper operation of known continuous feeding pile elevating mechanism is heavily dependent upon an attentive and alert operator because certain operations must be performed at particular times and preparatory steps must be taken for many of the operations. As a result an operator must keep all steps in mind and be prepared when each is to take place.

It is an important object of the present invention to provide an elevating mechanism of the type described which is simplified in operation, requires less operator attention and is more foolproof than the prior art mechanisms, and in which a new pile may be brought into position in less time than heretofore required.

Another object of the present invention is to provide a pile elevating mechanism of the type described which can be operated by one man.

Another object is to provide a new and an improved mechanism of the type described in which the main and auxiliary hoists are raised and lowered by means operable independently of each other and at any time during the elevating operation, and in which pile height detecting means is operable to control one or the other, or both, of the hoists simultaneously.

Yet another object is to provide a new and an improved pile elevating mechanism having main and auxiliary hoists controllable by pile height detecting means and in which the main hoist is automatically disconnected from the pile height detecting means when the auxiliary hoist takes the pile therefrom and preferably wherein the taking of the pallet by the auxiliary hoist automatically places it under the control of the pile height detecting means when the pile thereon is taken by the auxiliary hoist and can be thereafter raised and lowered by power independently of the detector and can again be placed under the control of the detector so that both hoists are raised together in response to a low level detection.

A further object of the present invention is to provide a new and an improved pile elevating mechanism having main and auxiliary hoists and in which the pallet may be Withdrawn to support the rear edge of the pile thereon with a relatively thin portion to permit the auxiliary and main hoists to be moved toward each and reduce the rear edge pile drop when the pallet is completely withdrawn, the auxiliary hoist and pallet being so constructed that the pallet is automatically stopped in proper rear pile edge-supporting position upon withdrawal of the pallet.

A still further object is the provision of a pile elevating mechanism as in the preceding object in which the pallet is stopped by a latch which is releasable by lifting the pallet relative thereto.

It is also an object of the present invention to provide a new and an improved method of operating the type of elevating mechanism described to provide a smooth change-over of the piles from one hoist to another and to facilitate the combining of the piles.

It is further an object of the present invention to provide a new and an improved pile elevating mechanism of the type described in which stops are moved into position against the rear edge of the remnant pile in response to pallet withdrawal.

Furthermore, it is an object to provide a pile elevating mechanism of the type described wherein the engagement and release of a latch member for arresting the withdrawal of the pallet on the auxiliary hoist are sensed to signal that the hoists are to move toward each other and that the pallet is to be withdrawn.

Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiment thereof made with reference to vthe accompanying drawings forming .a part of the a present specification and in which:

Fig; 1 is a side elevational viewof akpile elevating mechanism embodying the present; invention with parts v thereof cut away or removed;

'BFigK-Z'is afragmentary view lookingaftherear of the elevating mechanism shown in Fig. 1 and from the right-hand side of the mechanismas it is viewed in Fig. 1; 1 r a Fig. 3 is a vertical sectional view taken-approximately 'along line 33 of Fig. 1; r

Fig. 4 is a diagrammatic view showing the hoists of the, pile elevating mechanism-of Figi-l; 3 Fig. 5 isa fragmentaryflelevational yiewj with parts cut away and removed taken from -the=left-hand sidevof Fig.1; r

Fig. "6 is an enlarged'fragmentary 'view of a portionof Fig 5; I :7 V 4 i 1 V Fig, 7 is a sectional" view taken approximately from lines 7 7 of Fig.3; r r a Fig.8 is an enlarged of Fig.7; V a 1* Fig; 9 is a sectional view takenapproximatelyalong 7 lines 9-9, of Fig. '8;

vFigs. 10 and 11 are sectional views taken approximately from lines 10-10and11-11 of Fig. 3; 7

Figs. 12, 1'3, 14, 15, 16 and 17 are fragmentary views showing the locations of various switches;

Fig. 18 is a view of acontrol'panel for the mechanism taken looking from line 18-18 of Fig. 1; a

Figs. 19'and 19a constitute an across-the-line circuit diagram for the'elevating mechanism shown in Fig. 1 and in accordancewith conventional practice the lines of the diagram are numbered and the line numbers of the contacts of "the various coils are shown adjacent the coil;

Figs.'19b, sand :1 are locater tables for the relay coils, I switches and solenoids in the circuit diagram of Figs. 19, 19a; i

Fig. 20 is'a fragmentary view showing the pawl and ratchet mechanism for operating the main hoist; and a 1 Fig. 21 is a view showing a backstop member adapted for use in the elevating mechanism of Fig. l; V

The pile elevating mechanism: shown inv the drawing 7 comprises main and auxiliarypile hoists which operate to, support a-pile of sheets while thetop sheets are periodically'r'emoved therefrom and to elevate the pile to mainr tain the top of'the pile at anapproximate level required for-proper operation of sheet separating and forwarding means associated with the pile elevating mechanism. The sheet separating and forwarding'means comprises separating suckers 11 adapted to pick up the top sheet of the 'pile'and sheet forwarding" suckers 12'for forwarding the-separated sheet to conventional :pull-in rolls, not

shown, but which are disposed adjacent the'front of the pile'at approximately the level of the suckers 12 and are adapted to take'the sheet and 'feed it to a sheethandling' mechanism.

VIhe pile elevating mechanism shownfincludes front fstationary columns 15, 16' and rear'stationary uprights 17 and side frame members, 18,-19 extending along the op posite sides of the mechanism and connecting the front and rear uprights on that side of the mechanism, the member'18 joining front column and one rear upright 17, and side frame member 19joining front column 16 and the other rear upright 17. Transversely spaced, stationarytguides are provided between the front columns '15, 16 and are adapted. to engage the front of the piled sheets: being elevated .to guide the sheets in their vertical 'movement.

As previously statedjthe pile elevating mechanism ineludes a' pile hoist for elevating a pile of sheets to a level where the top sheets are to be'removed by the suc rers 11 with-the main pile hoist being operated intermittently to maintainithe top of the pile thereon' atlthe proper level.

.Theirnain ipile i-hoist includes: front and trearz'pulleys :23,

hono ees a e e fragmentary :view -of --a 505a V :54 7 24 mounted on the'side member 18 and over which cables 25, 26, respectively, are trained, and front and rear pulleys 27, 28, respectively, mounted on side frame member 19 and over which cables 30, 31, respectively, are trained. 5 The cables 25, 26 and 30, 31 have knobs at their lower ends adapted to be attached-to the ends of longitudinal rails 32, 33 which carry cross rails 34 that extend under a skidior'pallet platform '35 uponwhichapallet 36 is adapted to be supported, The pallet 36 carries thepile 10 of sheets to be removed one at a time "bythersheet'separating and forwarding mechanism. Thelongitudinalsrail 32 is connected to the ends of cables 25, 26ywhile'the longitudinal rail 33 is connected-to the ends of cables so, 31. v

The cables 25, 26 and .30, 31-- are" wound on individual drums 40 fixedto a drum shaft41 that extends between the front columns 15, 16 of the pile elevating mechanism and is generally supported therein; The drums 4 9' over which the'cables '25, -26 'arewound are' fixedto lthe near end of the shaft as the elevati-ng mechanisms-isviewed in v Fig. 1, and the drums over which the cables :30, 31 are wound are fixed tothe shaft 41 adjacent the remote end of the shaft-asviewed in Fig. 1. V g

It can now be seen that rotation of the shaft-41 to wind or unwind the cables of the main hoist onto or from theirrespective drums-will cause either the raising or the lowering of, the main hoist The drums 40 are narrow drums and the cables jwraponthemselves 'as they are wound onthe drums. The drums, therefore, have anteffective diameter which varieswith the amount of cable Iwound thereon and the amount ofJraising-andlowering of V themain hoist for agiven: angular rotation of the drums will depend upon the positionof the hoistswhich is indicative of the length of cable 'WOlll'ldiGll the drums.

In the preferredjand illustrated embodiment, the drum shaft41 has-a worm wheel 42fixedj to. the-shaft adiacent the drums for the cables25, lfi-and-adjacent the front column 15. The worm wheel 42 meshes with a worm 43- disposed below the worm wheel 42 and fixed 4 to a worm shaft-45 journaled in the column 15 and which extends outwardly thereof-and has an outer-end, square in'cross section, for receiving a crank46. The crank 46 has anopening therein opening into one side thereof, which opening is square at its inner end and cylindrical at 45 its outer end so that when the crank is moved rightwardly as viewed in Fig. 1 into driving relationship with the -w0rm shaft it is disposed axially inwardly on the shaft to enable the crank to engage'thesquare'opening therein with the shaft, but is disengaged 'ifimoved outwardly to where the cylindricalipart of thetopening'is about the square end'of the shaft. ,When the crank is engaged, rotation thereof by hand will rotate the worm wheel 42 and the shaft 41 to raise or lower the-main hoist manually. 5 The worm shaft 45 also has'a bevel gear 47 fixed thereto adjacent the worm 43. The bevel gear '47 meshes with a cooperating bevelgear 48 fixed to a drive shaft 50 extending transversely of-the front of-the elevating mechanism androtatable by power means to effect a power raising or lowering of the main hoist.

The drive shaft 50 may be selectively-driven in either direction from a motor 51mounted at the base of the column 15. The motor has a shaft 52 which is connected to drive a clutch shaft 53, disposed above the motor 51 and below the shaft 50 and journalled in the columns 15, 16, through a chain drive 54'which includes a gear or sprocket 55 fixed to the clutch1shaft'53 and an input or driving gear or sprocket 56 fixed to the motor shaft 52. The motor 51 and, in turn, the clutchshaft 53 are continuously operated in one direction. The clutch shaft 53 may be connected to driverthe drive shaft 50, to, in turn, effect a rotation of the cable drill-1115140, through, a gear train 58 which eifectsrotation-of the drive shaft 50 zin:one direction or through a 'geartrain59 which effects zrotation of :the tdi'ivesshaft '50 'ilBth OPPOSiE direction.

The gear train 58 includes agear'61 journaled on the .clutch shaft 53 and a clutch mechanism 62 for clutching the gear 61 to the shaft 53 for rotation therewith. The gear 61 is in mesh with an idler gear 63 which, in turn, meshes with a gear 64 secured to a gear shaft 65 and in mesh with a gear 66 fixed to the drive shaft 50. When the clutch 62 is engaged, the gear 61 will effect a driving of the drive shaft 50 through the train 58 in a direction opposite to the direction of rotation of the clutch shaft 53.

The gear train 59 comprises a gear 68 journaled on the clutch shaft 53 and a gear 70 in mesh with the gear 68 and fixed to the gear shaft 65. The gear 68 may be selectively clutched to the shaft 53 by operation of a clutch mechanism 71 to effect rotation of the gear 68 with the shaft 53. When the gear 68 rotates with the shaft 53, the gear shaft 65 and the gear 70 thereon and in mesh with the gear 68 rotate in the opposite direction to the clutch shaft 53 which, in turn, effects rotation of the drive shaft 50 in the same direction as the clutch shaft 53 through the medium of gears 64 and 66. The clutch mechanisms 62, 71 are disposed adjacent each other on the clutch shaft 53 and each includes a driving clutch plate 72 which is slidably keyed to the clutch shaft 53 and which is movable to engage a respective driven clutch plate 73 secured to the gear driven by the respective clutch mechanism. The clutch plates are spring biased to a disengaged position. The driving clutch plates 72 may be selectively engaged with the driven plates by operation of a clutch actuating lever 74 fixed to a shaft 74a journaled for rocking movement about an axis above the clutch shaft 53 that extends perpendicular with re spect to the shaft 53. The clutch actuating lever has a portion 75 which extends downwardly between the clutch plates 72 of the clutch mechanisms 62, 71 and carries a roller 76 which when the lever is swung in one direction engages and shifts the clutch plate 72 of the clutch mechanism 62 to engage the latter and actuate the drive shaft 50 in one direction and when swung in the other direction engages and moves the clutch plate 72 of the clutch mechanism 71 to its engaged position to rotate the shaft 50 in the opposite direction. The operating handle 74 extends upwardly above the pivot for the lever and in a position to be grasped by the operator. For purposes which will be explained hereinafter, the manual operating lever 74 is normally latched in a neutral position by a latch member 80 having a slot 81 therein adapted to receive a pin 81a on the manual operating lever 74. The latch member 80 must be moved clear of the pin 81a to permit the lever 74 to be operated to engage either the clutch 62 or the clutch 71 to drive the main hoist from the motor 51.

During operation, the main hoist is operated in increments from the press drive to maintain the top thereof or of the pile thereon at an appropriate feed level. The mechanism for raising the main hoist in increments or in a stepwise manner comprises a continuously rotating crank shaft 82 which extends across the front of the pile elevating mechanism. When the pile elevating mechanism is used in connection with feeding apparatus for delivering sheets to a printing press, the shaft 82 is preferably driven directly from the printing press drive so as to be timed therewith.

The crank shaft 82 has secured to its end adjacent the column 15 a crank 83 which is connected by a link 85 to reciprocate a pawl 84. As is best shown in Figs. 1 and 20, the pawl 84 is pivoted to one end of one arm 86 of a bell-crank lever 87 journaled on the drive shaft 50, and the lever 87 also having an arm 88 to which the connecting link 85 is pivotally connected to effect a continuous reciprocation of the lever 87 and pawl 84 from the continuously rotating crank 83. The pawl 84 is adapted to engage and advance, in increments, a ratchet Wheel 90 fixed to the drive shaft 50. The ratchet wheel 90 when rotated by the pawl 84 effects rotation of the shafts 50 in the direction necessary to raise the main hoist; The pawl 84 is disposed above the ratchet wheel and drops by gravity into engagement with the ratchet teeth of the ratchet wheel 90 unless positively prevented from doing so.

The pawl 84 may be prevented from engaging the teeth of the ratchet wheel 90 when the pawl is reciprocated by raising a pawl lift member 91. The lift member 91 includes a lift arm 92 that extends generally horizontally below the pawl 84, the arm 92 having an upper arcuate surface which is adapted to engage a roller 93 on the pawl 84 and to lift the pawl clear of the ratchet teeth 90 when the arm 92 and the lift member 91 are raised. The pawl lift member 91 is pivoted, as indicated at 94, so that rotation of the lift member 91 in a clockwise direction about the pivot 94 effects a lifting of pawl 84 and prevents it from engaging the teeth of the ratchet wheel 90. The pivotal connection between the pawl 84 and its supporting arm 36 of bell-crank lever 87 permits reciprocation of the bell-crank lever 87 by the crank 83 when the pawl is lifted.

When the main hoist is being operated under the control of pile height detecting means, the lift member 91 is raised when the top of the pile on the main hoist is at the proper level for removing sheets therefrom and the lift member 91 is lowered to permit the pawl 84 to engage the teeth on the ratchet wheel 90 when the level drops to a point where the main hoist should'be elevated. To this end, the pawl lift member 91 has a portion 96 which extends upwardly therefrom adjacent the pivot 94 and which is operated under the control of the pile height detecting means to raise and lower the pawl lift arm 91.

In the illustrated mechanism, the pile height detecting means is designated by the reference numeral 100 and is supported above the rear edge of the pile from which sheets are being separated by the separating suckers 11. As is shown in Fig. 1 and Fig. 11, the pile height detecting means comprises a detecting finger 101 which extends generally vertically and which is threaded into a support block 102 fixed to the end of a detecting arm 103 rockable on a shaft 104 extending transversely of the pile elevating mechanism and stationary during the operation of the elevating mechanism. The block 102 is angularly adjustable about an axis parallel to the shaft 104 and the detecting finger 101 may be threaded into or out of the block 102 to adjust the depending length of the finger.

The detecting arm 103 and, in turn, the detecting finger 101 is rocked toward engagement with the top rear edge of the pile from which sheets are being taken once during each cycle of operation, a cycle of operation occurring between the times each sheet is removed from the pile. The rocking of the detecting arm 103 is accomplished, in the illustrated embodiment, by means of a cam which is fixed to a continuously rotating cam shaft 105 is dis posed immediately above the shaft 104 which supports the detecting arm 103 and having a cam 106 fixed thereto for rotation therewith. The cam 106 cooperates with a cam follower 107 fixed to a portion of the detecting arm 103 on the side of the shaft 104 remote from the detecting finger 101 to efiect an oscillation of the detecting arm 103. The roller 107 is urged into engagement with the cam 106 by a spring 103 connected between the detecting arm 103 and a cam guard 110 fixed to a stationary shaft 111 above and parallel to the shafts 104, 105. The cam guard 110 also has portions 112 which function as a guard for the cam 106. When the cam 106 is rotated, the cam has a low portion 106a which allows the spring 108 to move the detecting arm 103 clockwise about the rockshaft 104, as the latter is viewed in Fig. 11 to move the detecting finger 101 downwardly toward engagement with the top of the pile. If the detecting finger 101 engages the top of the pile, the cam follower 107 will not follow the cam 106 and the rocking movement will stop until the high portion of the cam 106 lifts the detecting finger 102 from the pile when the high portion thereof engages exam-tee c am when it is riding toward the low portion,'the;arm

i103 rocks an angular amount which is greater than'when the level of the pile is suchfas to prevent the follower from'following the cam 106. V

When "the detecting arm 10'3'rocks 'on its shaft 104, atdet'ector rockshaft 113 extending parallel to the shaft 104 rearwardly and'downwardly thereo fis-rotatedor rocked an angular amount corresponding to the rocking of the detecting arm 103. The shaft 113 has an arm 114 "keyedthe'r'eto and extending upwardly therefromwithlthe upper end 'of 'thearm being connected to the detecting warm 103.by a link115 pivoted totthe arm 114 and to the rocker member 103on'the axis of the cam follower 107. It. can'be seen, therefore, that the angular rotation "of the shaft 113' is indicative of the height of the pile and the adjustment oftthe detector is such-that'when the shaft 113 rocks a predeterminedangular amount, it is a signal that the pile height is too low.

'The-en'd tof-the shaft113 adjacent the side frame 18 hasfixed thereto an arm 117 which carriesa roller 118 at its outer end that is engageable with a laterally extending flange 119 on a shaft-120 thatextends parallel "to the side frame member 18 and to the front column '15. When :the shaft 113 is oscillated, the arm 117 moves downwardly to engage the flange 1190f the shaft 120 to efifect a corre- V spending pivotal movementofthe shaftzlZll. The angular movement of the shaft 120 controls the pawl lift member 9L The shaft 129 is connected to control the pawl lift member 91% that when it oscillates counterclockwise, as viewed in'Fig. to a predetermined angular position,

the pawl 84, is allowed to engage the ratchet-wheel and when it is oscillated in the opposite direction apredeterthe forward end of the shaft and extends radially outwardly therefrom'and inwardly'of 'theelevating mechanism. A rod 122 is adjustably connected to theouter end of the arm 121 so as to move downwardly therewith and extends downwardly therefrom' to effect the rocking of a verticaltlatch member123 accordance with the rocking *ofthe'shaft 120. The latch member 123 is pivoted for irocking' movement about .a pivot pm '124 and extends downwardly:therefrom'and has a rearwardly extending am 125 whichiisconnected to the rod '122by'a noddle zpin connection'l26; A set screw'126a adjustably fixes the :noddle' pin 126 to rod 122; A spring 1261) is disposed iaboutihe rod'122 and engages the noddle pinand a -.-'frame member through which the lower endof'the rod 15122 freely slides. The spring'126b urges the rod '122 upwardly and,in turn, the latch member 123411 a counter- -'clockwise'direction,'as viewed in Fig; handshaft 120'in a clockwise direction as viewed inFig; 2. The flange :119 ,on shaft 120 is therefore urged toward engagement with 'the roller 118 rocked'by the detector shaft'113.

The latch member 123 is adapted to control the rocking movement of a bell-crank lever-127 which is rockable about apivot connection 128 and is connected to reciproca te the pawl lift arm91. (See Figsrl and 2 0.) The bellcrank lever- 127 includes an arm 130 which extends downa wardly to a position adjacent the'upper end of-the arm" ,96 of .pawllift member 91 and an arm 131 which extends forwardly from the pivot 128 to a position adjacent a cam 132 fixed to the crank shaft8 2 for rotation therewith. It

mined amount from the position 'where the pawl is en -gageable,' prevents-engagement of the pawl 84 'with the ratchet wheel 90. To thisend, an arm 121 is fixed 'to spring 1 34 cenneetedto ithe frame and which urges the bell-crank lever-'inva *clokbeuerank lever 127-andthe wise direction aboutiitspivot tojurge'the-camfollower 133 into engagementwith the eam132; If the camfollower -133 is prevented {from moving or "following the 'cam 132 when the'lowportionthereof approaches the camfollower 13 3, the pawl lift member 91 will be maintainedzin a raised :position since the lift -memb'er 91 is lifted by the bell-crank lever "when the 'cam follower .133 is riding on the high portion of the cam 132 'and' is lowered to permit engagement of the pawl 84'when1the follower 133 is ridingon the low portion'o'f'gcam 132. The latchlmember 3123 is pivoted above "the arm" 13 1 of the bell-crank "lever 127 "and when disposed inla vertical position engages a stop '131aon the arm '1-31andprevents the arm 131 and the cam follower 133,thereon from following the cam 13210 maintainthepawl lift memberin ailift position which keeps the :pawl'84jfrom engaging withtheratchet wheel 90, "If,"however, the pile. height level is detected to be tooilow, the latch'meniber 123 is moved to avposition out-of engagement'withthe stop 131iz,.which allows the bell-crank leverf127' to'be moved clockwise by the spring '134 .under the control of earn 132. This in turn frees the lift .arm 91 -to'.m0ve counterclockwise under theinfluence of gravity to allow the pawl 84 to engage the'teeth on .the ratchet wheel 9010 rotate the same and effectan incremental raising-of theImain hoist. It will be understood vthat the timing of the rocking of the lift member91 under the control of cam 132' is such that the lift arm 92 is downabefore thepawl 84 is actuated in the driving portion of its reciprocatory movement.

7 .When it -is desired to operatethe'main hoist manuallv or by the motors51, .the1pawl or pawl lift member 91 shouldtbe operated to :hold the pawl-84 out of engagement with the ratchet Wheel199, Forthis purpose, a mauuallyoperated lever. is-provided adjacent the manually operated crank 46; The actuating'lever' 144 is pivoted to the column 15 and has -.one-- end adapted to be grasped by the operatorand a portion which extends in- .wardly-toward the ratchet wheel '90'and the inner end end of arm 92 of the pawl lift member=91-andlifts the latter when the lever 142-is actuated to--araised;position, astshown inFig. 6. The rod141 slides through an opening in a lateral flangein latch lever SO-and is guided thereby. 1

The latch lever 80 which prevents operation of the clutch shiftinglever 74 is, as-mentioned above, pivoted to the columnl-S and has a portion designated'by the reference numenal 143 which maybe grasped by the operator tollift theilatchlever n80. The'lever'142 is provided with a pin-144 which extends overthelatch lever 80 so that when the latteri's raised to release the clutch actuating lever 74, the lever142 and, in turn, the pawl lift member s 91 are raised to assure that the pawl 84 does not engage the ratchet wheel 90 whilejthemain hoist'is being raised or lowered-by the motor '51, through the clutch mechamsm. a

In addition to thezmechanism described above, a solenoid 145-is mounted below the latch lever and is entergizabletoi-elfect' a lifting ofhthe latch lever 80 and lever 14 2. 'I'h'e'solen'oid 145-has an armature 146 which extends upwardly therefrom and which is raised when'the solenoid is energized, The upper end :of'the armature 146 is connected to therlatchleven80 by a rod 147 pivoted'onthe' armatureand receivedin an opening in a 'fiange on the latchJlever. .A spring 148 is disposed about the rod and abutst'a shoulder or collar on the rod and the underside 'ofithe' flange;of:theilatch. lever.

As is aevident stfrom i the foregoing, Pthe1 pile height ide- 'atectingimeansziszetfeetivedhroughztheratcheewheel 90431161 the pawl 84 to intermittently efiect an incremental raising of the main hoist to maintain the top of a pile supported thereon at the proper level for the suckers 11 to remove sheets therefrom. After the main hoist has been elevated a predetermined amount, preferably when approximately seven inches of remnant pile remains on the pallet, the pallet supporting the pile is transferred from the main hoist to an auxiliary hoist disposed above the main hoist and adapted to continue the intermittent elevation of the remnant pile to maintain the top thereof at feed level while a new pile is being brought into position on the main hoist. In the illustrated embodiment,-the auxiliary hoist comprises a rectangular frame 150 supported above the main hoist by four lead screws 151. One of the lead screws 151 is disposed at each corner of the frame 150 and a nut 152 mounted on each corner of the rectangular frame threads onto the adjacent lead screw. Rotation of the lead screws 151 in one direction raises the frame 150, while rotation in the opposite direction lowers the frame 150.

The frame 150 has a pair of front arms 154 depending therefrom adjacent the opposite front sides of the frame and a pair of rear arms 155 depending therefrom adjacent the opposite sides of the frame at the rear of the mechanism. Each pair of front and rear arms adjacent the corresponding sides of the pile elevating mechanism is joined by a pallet supporting rail extending front to rear, with the pallet supporting rail adjacent the side frame member 18 being designated by the reference numeral 156, and the rail along the side of the press adjacent the side frame member 19 being designated by the reference numeral 157. The rails 156, 157 each have a plurality of rollers 156a, 157a mounted on the inner side thereof so as to extend inwardly therefrom in position to engage the underside of a pallet and support the latter on the auxiliary hoist. The arms 154. 155 are connected to the frame 150 for swinging movement toward and away from each other, i.e., the arms on one side of the frame 150 are swingable toward and away from the arms on the other side of the frame so that the arms may be sung to and from pallet-engaging position. A l-atch member 158 is mounted on a rod 163 carried by front and rear blocks 164 fixed to the rail 157. The rod 163 is axially slidable in the blocks 164 and the latch member is adjustable along the rod.

The arms 154, 155 may be swung to and from palletengaging position by the operation of a crank 160 supported on a rear transverse frame member 161 comprising spaced parallel plate members and constituting a part of the frame 150 and joining the nuts 152 at the rear end of the frame 150. The crank 160 is fixed to a shaft 162 which mounts -a pair of eccentrics, not shown in detail, that have eccentric straps which are tied to the upper ends of the rear arms 155 by links 165. The eccentrics and their cooperating straps are not described in detail since the mechanism is disclosed in application Serial No. 735,446, filed by Norman W. Taylor on May 12, 1958, and per se form no part of the present invention. It should be noted, however, that the shaft 162 extends inwardly of the frame member 161 for purposes hereinafter explained in detail.

To raise and lower the frame 159 and the arms 154, 155, the screws 151 are rotated by a reversible motor 166 mounted on a bracket 167 supported by the front column 16. The motor 166 is connected by means of reduction gearing 166a to drive ashaft 168 extending across the elevating mechanism at the front thereof and having bevel gears thereon meshing with bevel gears 171, 172 fixed to shafts 173, 174, respectively, that extend along the opposite sides of the pile elevating mechanism with the shaft 173 extending along the near side of the mechanism, as viewed in Figs. 1 and 4. The shafts 173, 174 have bevel gears 175 fixed thereto which mate with respective ones of bevel gears 176 fixed to the lead screws 151 to effect rotation of the latter. It can now be seen After the auxiliary hoist has been operated to take a pallet with a remnant pile of sheets thereon from the main hoist, the motor' 166 is operated incrementally under the control of the pile height detector to maintain the top of the remnant pile at the proper level for the suckers 11 to remove sheets therefrom. To this end, a switch 180 (see Fig. 20), is mounted adjacent the bell-crank lever 127. It will be recalled that the bell-crank lever 127 is reciprocated by the spring 134 and the cam 132 which is continuously rotated during the operation of the pile elevating mechanism when the pile height detecting mechanism detects a low level, the pile height detecting mechanism 100 operating through the latch 123 to release the bell-crank lever 127 for control by the spring 134 and cam 132. If the pile is low, the latch member 123, as described in describing the main hoist, is moved to allow the lever 127 to follow the cam 132. If the pile level is at or above the minimum to be maintained, the latch prevents the bell-crank lever 127 from following the cam 132 and the movement thereof is, therefore, indicative of the need for raising the top of the pile from which the sheets are being taken. The switch 180 has an actuator 180a engaged by the arm of the bell-crank lever 127 to momentarily close the switch when the latch member 123 allows reciprocation thereofat the time the pile level is low. The switch is of the type which is closed momentarily by the movement of the arm 130 in its clockwise direction, to engage the actuator a as viewed in Fig. 20, but is not actuated by movement in the counterclockwise direction. The actuator 180a is a reciprocable rod spring-biased toward engagement with the mm 130, but the details of the switch and its actuator are not shown since it is commercially available and elevating mechanisms using such a switch are conventional.

The closing of the switch 180 will, only if a pile is on the auxiliary hoist, eifect energization of the motor 166 to raise the auxiliary hoist. The rotation of the motor 166 to raise the auxiliary hoist will be stopped after the pile has been raised sufliciently to enable spring 126b to cause latch 123 to lock out the lever 127 and after the auxiliary hoist has been raised a predetermined incremental amount. The stopping of the motor is caused by the operation of a pair of dogs 181, 182 fixed to the opposite sides of the shaft 174 adjacent the front end thereof. The dogs 181, 182 are spaced 180 apart so that the ends are adapted to strike the actuator of a limit switch 183 mounted adjacent the shaft 174. As the shaft 174 is rotated, one of the dogs within 180 of revolution will momentarily actuate the switch 183 as it moves past its actuator. The switch 183 is connected into the motor circuit for the motor 166 to effect de-energization of the motor if the energization thereof has been effected by the momentary closing of the switch 180. Since the bellcrank lever 127 is reciprocated in each cycle when the pile is low, the motor may be repeatedly energized and deenergized by the combined operation of the switch 180 and the switch 183 until the auxiliary hoist is raised sufiiciently to enable the latch member 123 to be moved into position to prevent the bell-crank lever 127 from reciprocating to close the switch 180.

The auxiliary hoist is placed under the control of the pile height detecting means and the pawl 84 lifted whenever the auxiliary hoist takes a pile from the main hoist and preferably remains under the control of the detecting means as long as apallet is in supporting position on the auxiliary hoist. To this end, sensing or signalling means :inoperative position;

undersideof the pallet.

wwithdrawn. T'Ihis is because detector operate "on the rearedgeof the pile and-itis unheight detector. 7

pallets'haye been provided with. a step atthe forward'end thereof, as is shown in thedrawings and asdescribed in the aforementioned Royer;

'lwardly ofthe frontedge n *pallet is withdrawn the'pallet 'is temporarilyposrtioned palletgis withdrawn to the Ti comprising a plurality of limit switches are provided on ithe-rails156, 157, there being a limit switch 190 on eaoh rail adjacent the front end of the rail and a 'limit'switc'h .191 adjacent the rear end of each railfor reasons which will-appearlhereinafter. The switches 190 are closed by a pallet on the ;auxiliary hoist when 'it is in normal pile-supportingposition,;and switches 191 aresclo'sed by the pallet when itiis-being withdrawn and while'it is supporting only the rear edge of the remnant pile, as described hereinafter.

The :switches 190, 191 are connected into the control circuit for. the motor '166 so that if either set is actuated,

the-switch180 may be rendered effective to operate or energize the motor 166 and when-neither. set is actuated,

V :the switch 180 is ineffective to elfectenergizationof the "unotor 166. I xi 7 1 1,

' .After the. auxiliaryhoist has been elevated to a prede- -termined'ipoint where the pile. thereon has only a rela- Etively few :number ofsheets left and preferably whenfthe ipileis approximately 1 /2." high, the pallet supporting the pile'on'the auxiliaryhoist iswithdrawn in a first stage to deposit the majority of:the remnant pile" thereon onto the -top:of-a1;ne,w pile on the main hoist. ;To support the lpallet ash, is withdrawn from'below the remnantpile; each of. the rails 156, 157 is provided with an extension 1195 which is connected tol-the rear end of the correspond- 1ing-rails.156,'157 and swings between an operative position-fin-alignment with the rail and a generally vertical Each rail '195 has. ailink 196 pivotedithereto adjacent its outer en'd,the link,in turn, zbeing connectedto the adjacent rear arm 1155 by a link 197.

"1 2 wise as shown'in Figs. 7 and .8 about the pivot therefor by gravityjaided by a spring 207 disposed under the left end--of latch member .158 so thatan upper portion 158a;at the forward endithereofis urged vupwardly into engagement with the undersidegof the pallet on the auxiliary hoist and "toward moyement into the; recess 294. The upper forward portion 1580 of the latch member forms an abutment which, when the recess 204 r is moved to a position over the latch member, engages the forward side of the rece ss 204 which forms a coop crating abutment to prevent or arrest further withdrawal of the pallet. The 'block 206 is adjustably slidable along the rod 163 which extends along the underside of the rail 157 and which is supported for limited'axial movemerit bythe aforementioned front and rear blocks 1 64 ClLSpOSBd at the forward and rear ends of the bar 163 and fixed to the rail 157. i Ihe block 206-abuts an adjustable clamp. collar 206a,.disposed .rearwardly'of the blocln The'bar 163;,is normally urgedforwardly .by

'a spring 210 to move a collar 2.11 fixed thereto into engagement with the front block 164. Thespring 210 is positioned between the frontblock 164 and a nut lltiafixed to the forward-end of the rod163. When the latch member 158 is. engaged -by the forward side jof'the recess lil fthe force tending to'withdraw the pallet andthe momentum of the, pallet cause the spring 219 to yield and-permit lirnited rearward axiahmovea limit switch 170 ment of the rod 163 to actuate ,jmounted adjacentthe rear end of rod .163 tosignal .Thelink197 is pivoted to both the link 196.and the ad- .jacentrreartarm 155 and-a stop member198 is secured :to the;lirik I97 to'engagethe' link 196 'when'the rail extension 195 has moved toits position in'alignment' with the'corresponding one of the rails .1156, 15710 prevent tfurther downward movement of the extension. e

For purposes which will'be described'hereinafter, it .isvdesir'able' to sense the initial withdrawal of the. pallet and, to this end, a limit switch 202 is fixed tolthe. forward end of the rail 157 and has an actuating arrn-203 which "extends iupwardlyto be received in arecess 204 in the 7 When the' pallet is withdrawn, the actuator .2ti'3ridesout'of lthe recess-204 to momentarily actuate thelimit switchi202 to signalthe initial withdrawal of the pallet.

"'Whencon'ibining the pile on the auxiliary hoist with the pile 'on'lthe mainihoisnpit is desirable ,to minimize the dIOPTOf the rear'edge of theremnantpileasthe pallet is the suckers and the pile height desirable to have-a drop suchtthat the rear edge falls belowthe operating range :forthe suckers and the pile f To :enable the drop; to :-be minimized,

application. The 'step 7 comprises aithin portion205 which-extends along and outof. the pallet and, when the with the-portion .295 under the rear'edge of the remnant pile and the main pile' hoist operated tomove the top of the pile thereon into the step and ,closer-tothe bottom of a "ber 158'-is"pivoted to a block 1316 and is iurgedijclocbi ,tively move the remnant Sponding limit switch gram. While the palletis in its partially withdrawn position, it keeps the pear to provide a sensing of 'the' and removed from the' rails V sions 195 thereof the extensions are folded to their that the latch member158 has been received in the recess 2%. The nut 210a is adjustable toprovide proper preloadlin the spring 219 to both prevent friction from the underside ofthe pallet-from urging the bar 163 rearwardly during-.withdrawal before the'recess 204 comes into position, and also to prevent thettwo springs Zitifrom urging the pallet forwardly when only the 'thin portion 205 of the pallet, is .under the remnant pile.

After'the latch member 158 is engaged, and the new pile. has been raised-into. thestep provided in the pallet, the main hoist or the auxiliary hoist is operated to relapile andlthe new pile on the other to lift the forward pormain hoisttoward each The lifting-of vthe pallet or. of

tion 205 of the pallet.

the forwardedge of the pallet causes thepallet to clear the latch member 158, allowing the spring 210 to return therjrod 163 and signal the necessity toco nplete withdrawal of the pallet.

Preferably, a latch member and limit switch corre' spondingto latch member 1 58 and switch may be providedonrail 156dtog'ether with .a rod corresponding to rod 163 and the .biasing means therefor. ,While a corresponding latchmember is not shown, a corre- 170 is shownin the circuit dialimit switches 19L actuated fact that the pallet is still below the remnant pile. When the. pallet is withdrawn gfully, itclears the switches-19 1 and the operation thereofsignals that thepiles have been combined and switches pile raising control by the. pile height detecting means to the main hoist only. 'After the; pallet is withdrawn 156, 157 and the extengenerally vertical position and a limit switch 208'is actuated by the swingingmovement of the link l96to signal thatthe arms 1.54, 155' shonldbe swung out. The limit switch 208 is mounted adjacent the underside of the extension ofrthe rail 157 and is operated by a dog 209 secured to theend oflink 196.

After the pallethas been withdrawn, the crank 16% is operated to swing out the. arms 154,155 of the auxiliary-hoist. The shaft 162 of the crank 169has switch actuating dogs 16011, 16%, on its innerend and when the crank is operated, the dogs are. adapted to actuate limit.. w. tsh s. 2 .2 lilmsmmd on: th am m m e 1 thereof.

in adjacent the inner end of Shaft 162 (see Fig. 13).

'in the other direction, do not effect operation of the switch. The switches and, actuators therefor are of a conventional commercially available type and therefore are not shown or described in detail. The switch 212 is set up so that the switch is momentarily actuated by the dog 169a when the crank 160 is rotated in a direction to swing the arms out. When the switch 212 is actuated momentarily, the auxiliary hoist motor 166 is operated to move the hoist downwardly in a continuous manner to a lower limit position where the hoist is adapted to take the next pallet to be elevated thereby fiom the main hoist. The downward movement of the auxiliary hoist is stopped when it reaches the desired lower limit by a limitswitch 215 (Fig. 12) mounted adjacent the lower end of the front lead screw 151 adjacent the right-hand side of the pile elevating mechanism, as the latter is viewed in Fig. 3.

The limit switch 213 operated by the rotation of the crank 160 is set up so that the switch is momentarily actuated to 'a closed position by the dog 16% on the rotation of the crank in the direction necessary to swing in the arms. The actuation of the switch 212 causes the motor 166 to be energized to move the frame 150 detecting means.

The main hoist actuates a limit switch 216 (Fig. 15)

'to signal when the arms of the auxiliary hoist should be swung in to take a pallet from the main hoist.

The limit switch 216 is supported on the front column 15 and is engaged by a vertical plate 217 fixed to the longitudinal rail 32 of the main hoist so as to move upwardly and downwardly therewith. Preferably, the limit switch 216 is actuated when the main hoist has been elevated to a position indicating that. approximately seven inches of sheet pile remain thereon. The upward movement of the main hoist is limited by limit switches 218, there being such a limit switch mounted on each of the front columns 15, 16 in position to be actuated by the plate 217 on the longitudinal rail 32 and a plate 217a on the longitudinal rail 33. (See Fig. 3.)

In accordance with the preferred embodiment of the present invention, the operation of the pile elevating I mechanism is facilitated and simplified by a control panel which includes signals for performing certain operations at the proper time.

The control panel is designated by the reference numeral 220 and is mounted on the cover of the elevating mechanism at the rear side (See Figs. 1 and 18.) The control panel 220 includes a signal block 221 having a light 222 (Fig. 19a) therein which is energized when the arms of the auxiliary hoist are to be swung in to pallet-engaging position. The energization of the lamp 222 is controlled by the limit switch 216. Immediately below the block 221 on the control panel is a block 224 which indicates that the main hoist should be lowered when a lamp 225 therein is energized. The lamp 225 may be energized after the auxiliary hoist has taken the pallet from the main hoist and the energization of the lamp 225 is controlled by a limit switch 226 (Fig. 16) mounted on the front arm 154 of the auxiliary hoist on the left-hand side of the elevating mechanism, as viewed in Fig. 3, and by the 1 limit switch 216 which is actuated by the main hoist when the pile thereon is to be taken by the auxiliary hoist. The limit switch 226 is a safety switch and is actuated by the pallet on the auxiliary hoist if the main hoist,

with a pile thereon, is elevated so that it engages the pallet and lifts the same from the auxiliary hoist. .If

this happens, the limit switch 226 is operated and the Lower Main Hoist signal 224 energized. Immediately below the main hoist block is a Pull Pallet block 228 A block 233 is disposed immediately below the block 228 and is illuminated to indicate that the pallet on the auxiliary hoist has been withdrawn to a position where its thin forward portion 205 thereof is disposed under the rear edge of the remnant pile and that the hoists are to be operated to relatively move the hoists to lift the pallet from the latch members 158 prior to completing withdrawal of the pallet. The energization of the amp 234 is controlled by the limit switches and 170 responsive to the operation of the latch members for engaging the pallet. A legend block 236 is disposed on the main control panel 220 immediately below the legend block 233 and has a lamp 237 which is energized to indicate that the arms of the auxiliary hoist are to be swung out. The energization of lamp 237 is controlled by the limit switch 208 actuated by the raising of the rail extensions 195. i

In addition to the above legend blocks, the control panel 220 includes Raise and Lower start buttons 238, 239, respectively, for the motor 166 and Stop button 240 for stopping the operation of the auxiliary hoist motor and a Synchronize push button switch 242 which is actuatable to render the pile height detecting means effective to control both the main and auxiliary hoists and a lamp 243 to indicate that both hoists are under the control of the detecting means, which may be termed synchronization. The panel also includes Power-0n and Power-Off push button switches 244a, 2445 for controlling the connection of the control circuit to the mains and a lamp 244c indicating when control power is on.

The controls for the auxiliary hoist may be best understood by reference to the circuit diagram of Figs. 19, 19a. The Power-On push button switch 244a (see Figs. 19, 19a), when depressed, effects energization of a Power relay coil 245 by connecting one side thereof to an L1 terminal of the secondary of a supply transformer having terminals labeled L1, L2. The other side of the relay coil 245 is connected directly to L2. The connection of the relay coil 245 to L1 is through the normally closed contacts of Power-Off push button switch 24411. The energization of Power relay coil 245 closes its normally open contacts 245a, 245b and opens its normally closed contacts 245c. The contacts 245a complete a holding circuit across Power-On switch 244a and the closing of contacts 245b connects a line, hereinafter designated as L1c, to the terminal L1 of the transformer to supply power to the control circuit. It will be noted that the control power is killed and the Power relay coil 245 de-energized if Power-Off push button switch 244b is operated.

When the Raise push button switch 238 is actuated, it closes two sets of normally open contacts 246a, 246b. The closing of the contacts 246a completes the circuit for energizing an up relay coil 247. When the lower push button switch 239 is actuated, it closes normally open contacts 248 to effect energization of a down relay coil 250. The relay coils 247, 250 actuate contacts 247a and 250a, respectively, in the phases for energizing the motor 166 and, when closed, eflect encrgization of the motor to cause it to rotate in difierent'directions. In addition to the contacts 247a, 250a, the

, fup. i-telay coil 247 also .has .norrnallyl19 d, interlocl;-i v .ing .contacts -.24'/';b. in the circuit for energizing -.dow n -,-:e1ay i and norm ly p ncontac .z. 1c-.fo mak n a-holding'clrcultpacross.Raise push ,hutton switch-E8, .andthe dowhirelay coil250 has normally'closed,;irr-

terloekingcontacts in thecircuit forenergizingthe up relay 247 and normally opncontacts 250a. which vmake aholding circuit across the Lower pushbut- .;ton .swi-tch v239. When the Raise push button switch 238 is depressed, the contacts 246:; thereof connect one sideof the up relay coil 2 47 to Llc through a circuit .whichcomprises the normallyclosed contactsof. Stop .push button switch 240, one of the normally closed contactsofswitch 246 being connected to Llc and the other being connected toone of the contacts 246a of @Raiee ..push buttonswitch 238'by aconnection 252, and the Qotherflcontact of the contacts 246a being connected to I 256. 1,(See; Fig. 12;) When .the 'up relay coil 2117 .iisenergized, its contaets1247c complete ,a holding circuit about the Raise pushbutt'on,switchj238 asymentioned above; :The up relay coil 247 will bermaintained-uenaergized 'untilaeither' the intermittentlimit switch 183;;the high limit switch 256, the stop push button..2 40, or one of the interlocking contacts in the circuit islo'penedQ It {will he noted that .a' normally: closed parallel circuit 257 ispconnectedacross the intermittent limitlswitch183and ,includesinormally closed.contacts;260a actuated..by..a

--fswing.-in relay coil 260 'normallyfclosed contacts 261a actuated by a' fchang'e -ov'er. relaycoil 2.61. Th contacts: 260a, 261a are jnormallyv closed, vi.e.,* the, relay coils 260, 261 are normally de-ener'gized, whena pallet .is not present. on the auxiliary :hoist, or; the arms 154, 155 arenotbeing swung in to take a pallet. Therefore,

long as a pallet is noton the auxilia'ryhoistor. the

auxiliary-hoist arms are not being operated .to takea ,pallet f rorn the main hoist, thefoperationof intermittent 'limit switch'183 will not affect the energization of fup relaycoil247;

(the; momentary closing of the switch 213 as thearrnslot t e uxili ry -;l.1,0i st;.are swung in .also s'ets. up a circuit". to .,,eflect a.raisingof .the auxiliaryhoist to lift' a: pallet. from theimainhoist and to place: the. auxiliary :hoist under palletfislifted b'y;the auxiliary hoist as'sign'alle'd by the actuation .otthelimit-switches .190 and the energiz'a- .:tion of fchangemver. relay coil261; a

tThe .momentary :energization of swing-in. relay coil 260; closes normallyopen contacts 260b, and in addi- ..-tion momentarily opensand again closes contacts-260a,

previously mentioned, for efiecting the energization of a relay coil 263 from Lie-,the relay coil 263 actuating .normally open contacts 263a, which, when closed, com- .plete..a circuit across thecontacts of Raise" push but The ienergization of .thc :iswingein relaycoil. 260by a .50 the .control .1 of; the pile .heightl detectoriel tlll, when .the e Titonigswitch .238 and efiect energization of up relay .247. The circuit for ,lenergizing the relay coil 263 includes normally closed contacts 265a on the L2 side of contacts 26% actuated by a time-delay relay coil 265.

.The time-delay relay. coil 265 is "connected across its contacts 265:; and the (relay. coil 265 'is energized when- .l everxrelay 263 is energized and operates after a prede-. -termined time'delay of approximately one-halfsecond ltocopen the eircuit for energizingrelay coil 263 from Llc. It can'b e seen from the above, that asthegarrns o f thel auxiliary hoistare swung in, the relay, coils 60 ancl gtiii will operate to energize the up relay coil 247 fiiQPpcd in plosed, the time-delay relay coil 265 will oprateto'dec o ntacts- 247c so thatit will .notbe -.dc;energized when qq iml siefief laiiF il ai l hoist -'w seuntil the circuit for energizing coil .247

, for some reason, the arms, 154,.155jare is'brolsen v, a position' which maintains lthe switchi. 2 13 energize the relay coil-263 to. prevent repeated operation of the motor 166. Whilethe intermittent switch 183 would be efiective to defenerg zejt e Pii y i this condition, since the contacts 26 0a in the parallel connection ;257 across the switch will also be fopelnthe up relay coil could beagain energized by pushing raise button 238 to close 246a and 2416b tohypags the circuits through switch 183 and lead 257. Under .s ch c i n, the auxi i ryh st. =an.Iai ;m;ti ..S tQ

183 next opens after button 238 is released.

' The p relay de n ma cond t on o tr nsi ring a Pallet f o t e-m to he. ll i ia y oi tw .remainenergized until the pallet closes both palletsensing switches 190 carried bythe rails 156,,157. Each ofthe switches 190 has one ofthe switcheslgl connected in parallel therewith and switches 19 0 are c'o1inected in series to complete a circuit whenfooth are closedbetwee'n Llcand one side of the change-over relay. coil 26 1. The otherfside ofthef' relay coil 26. is connected directly toLZ. x m' The energization of change-over relay coil ;261,'opens the normally closed contacts261afin the parallel connection 257 torender the intermittent switch 183 reflecerated by one of the dogs 181,1;18210 sto'p.;the raising flot'lth auxiliary hoist. It .can be :seen, the'refo'rmithat when the arms 154,155 are'swung in, the auxiliaryhoist will raise until .the' palletrs'ensin'g switches J are actuated to render intermittent switch 18 3efiectiye todeenergize up relay coil 247.

The i .change-over relay ..co1l 261 also factuates' Inormally open 'contacts-261b connected in a" series .con-

nection with the pile height detector switchf1801ai1'd acrossthe contacts 260b1so thatwhen both the contacts 261]; and the pile height .detector switch::are closed, the relay coil263. and time-delay relay'coil 265 .are

energized from Llc to efiect energization of the p relay coil 247. During norm al operation, the up relay coil will remain energized until the intermittent switch 183 eflects its'de en'ergization, as described above. It

3 can now be seen that .whenfa pallet is on the auxiliary hoist, the momentary closing offswitch' 180 will effect an incremental raising of the auxiliaryhoistf Since'the hell-crank lever 127 r (Fig. 20) foroperating switch: 180 is capable iof belng reciprocate'd once ine'achcycle when the pile is low, the closing jof th'e; switch 180 is only 'rnoment'a'ry and it is opened ineach cycle 'to-de-enlen relay'coi1263 andTif-the pileis still'low inthe next cycle switch 1 80 willagai n close to' again eliect another incremental raising of the auxiliary hoist.

The 'rel ay coil'25fl'is a limit relay coil andhas, as

men ionedileremb rma 3 1 5 inlerldcjking contacts in theicircuit for e ner:gizing"fupifrelay coil 247, th e cOntacts'Being eenneele between he -relay and n2 'ljhe fl m rrr'elay eoilj254 'is arra gned infth'le event that the height of'the' pile raises above-an x mum level.

this occurs, the top 'ofthe pileiactuates a'limit switch 270 '(see -Fig. 13) having normally bpe ri' contacts to connect one of elay'l'c oil 254tb1L1Q5ndtojefta .a l rsi at qen t latter w el hwe t fi in .thecircuit for; energiiing the up 'relay'247.. Sirni- "larly, it will be noted that if the auxiliary hoist reaches its upper limit it will'operatedimit switch 256 (see Fig. 12)to' also'eifect a cle energization of th up relay coil.

lt' will be noted that time delay contacts "2654 will prevent repeated energization and'de-enei'giiation of the motor 166 in the. event the-switch: .180 isjm'aintained closed. i 1 I 1 r i ':Preterably;the iitaiseinush button switch '238 has 17 its contacts 246b connected to complete a circuit across the intermittent limit switch 183 and the parallel connection 257 so that the hoist can be raised under the control of the operator even though the change-over relay coil 261 is energized by the presence of a pallet on the auxiliary hoist and the intermittent switch 183 is open. To this end, the L2 side of the contacts 246a of the Raise switch 238 is connected to one of the contacts 24Gb and the other of the contacts 2461) is connected to the intermittent switch 183 on the L2 side thereof. It can be seen that, whenever the push button switch 238 is depressed, a circuit will 'be completed to energize up relay coil 247 regardless of the condition of switch 183 or the parallel connection 257. After the up relay coil is energized, it will be apparent that the holding contacts 247a thereof will hold the circuit even though the limit switch 183 or its parallel connection 257 is open, as long as the push button switch 238 is held closed.

The above description has set out the control for the auxiliary hoist motor when it is desired to elevate the motor by depressing the push button switch 238 and when the motor is under the control of the pile height detecting means. The auxiliary hoist, however,.may be lowered at any time, regardless of whether it is under the control of the pile height detecting means, by pushing the Stop switch 249 and then the Lower push button switch 239. As stated hereinbe'fore, the depression of this switch completes a circuit for energizing the down relay coil 25?. and will efiect energization of the down relay coil only if the up relay coil is de-energized, since the circuit for energizing the relay coil 250 includes interlocking, normally closed contacts 247!) actuated by up relay coil 247. The circuit for energizing the down relay 259 may be traced on the circuit diagram from Llc through Stop push button switch 240, the connection 252, a connection 281 to one of the contacts of the push button switch 239 and a connection 282 from the other contact of the switch 239 to the L1 side of the relay coil 250 and from the other side of the relay coil to L2 through a connection including the lower limit switch 215. The energization of the down relay coil 250 closes its normally open contacts 2500 in a parallel connection 284 about the push button switch 239 to provide a self-holding circuit which can be broken by opening lower limit switch 215 (see Fig. 12), or contacts 285a actuated with a time delay by a relay coil 285 and connected in series with contacts 2580 in the connection 284. The time-delay relay coil 285 is energized to break the holding circuit through parallel connection 284 in a manner described hereinafter. The limit switch 212 (Fig. 13) is closed momentarily as the arms 154, 155 of the auxiliary hoist are swung out to initiate movement of the auxiliary hoist downwardly to its lower limit position determined by the position of the lower-limit switch 215. When the limit switch 212 is closed, it completes a circuit from Llc through the limit switch 212 to energize a swung-out relay coil 287. The relay coil 287 actuates normally open contacts 287a and normally closed contacts 287b. The normally open contacts 287a are connected in parallel across the down push button switch 239 and the parallel connection 284 and, when closed, connect the down relay coil 250 to Llc through the Stop push button switch 240. g

The down relay 250 for the auxiliary hoist may also be energized by the closing of contacts 290a actuated by a relay coil 290 which is connected in parallel with the relay coil 285. The relays 285 and 290 will be explained in more detail hereinafter.

The energization of the change-over relay coil 261 upon the taking of a pallet by the auxiliary hoist not only places the auxiliary hoist motor 166 under the control of the pile height detector, as described above, but

also sets up circuits for controlling and indicating various operations which take place during the change-over from the main hoist to the auxiliary hoist and during the later combining of the piles on the auxiliary and main hoist. When the pallet is taken by the auxiliary hoist and the change-over relay coil 261 is energized, it closes -contacts 2610 in a connection 291 connected to Llc to connect Llc to a connection 292 which is connected through a connection 293 to one side of the solenoid 145 (Fig. 6) for lifting the pawl 84 clear of the ratchet wheel to remove the main hoist from the control of the pile height detector. The connection 293 to the solenoid includes normally open contacts 295a actuated by a relay coil 295 which is energized on the closing of the contacts 2610 of the change-over relay coil 261.- The relay coil 295 is connected to the connection 291, including the contacts 2610 of the changeover relay coil, and then to Llc by a circuit which includes the normally closed contacts 297 of the Synchronize push button switch 242 connected in series with normally open contacts 298a actuated by a relay coil 298, having normally open contacts 295b being connected in parallel with contacts 298a. The normally open contacts 298a are closed to energize relay coil 295 and, in turn, solenoid 145 when the relay coil 298 is energized, the latter coil being energized by the closing of the change-over relay contacts 261:: through a circuit which includes normally closed contacts 299a actuated with a time delay by a relay coil 299. The relay coil 298 is, therefore, normally energized as soon as connection 292 is connected to Llc. The circuit for energizing relay coil 298 from the time delay contacts 299a comprises a connection 381 which includes the normally closed contacts 302a of a relay coil 302. The relay coil 299, as stated above, is a time-delay relay and the circuit for energizing the relay coil 298 through the contacts 299a is broken a predetermined time after it is made by the operation of the time-delay relay coil 299 and which is energized simultaneously with the relay coil 298 upon closing of the contacts 261a. Surnmarizing, the energization of relay coil 298 closes its normally open contacts 298a in the circuit for energizing relay coil 295 and the energization of relay coil 295 closes its normally open contacts 295a in the circuit for energizing the solenoid 145 to lift the pawl clear of the ratchet wheel 90 and to release the latch lever 80. When the relay coil 295 is energized to energize solenoid 145, it closes its holding contacts 29517 to complete a self-holding circuit about the contacts 298:: of the relay coil 298. The energization of the relay coil 295 also closes normally open contacts 295a in the energizing circuit for a relay coil 302. The contacts 295a and the relay coil 302 are series connected across the time-delay relay 299 and when the relay coil 295 operates it closes the contacts 2950 to effect energization of the relay coil 302 from connection 292. The operation of relay coil 302 opens its normally closed contacts 302a in the circuit for the relay coil 298 to de-energize the latter and open its contacts 298a, 298b. The contacts 298a are in the circuit for energizing the coil 295, While the contacts 29812 are connected in parallel with the time-delay contacts 299a of the relay 299. The contacts 298b will assure that the opening of the contacts 299a doesnot tie-energize relay coil 298 before relay coil 295 is energized to lift the pawl 84. If the contacts 299a were opened before the relay coil 298 were energized to close its contacts to energize the relay coil 295 to, in turn, close contacts to energize the solenoid 145, the sequence of operations would not occur and the pawl would not be lifted.

In the preferred and illustrated mechanism, an alarm sounds and a light is illuminated, either continuously or in an intermittent manner, under each of the conditions when the arms of the auxiliary hoist are to be swung in 7 an energization of the change-over relay 261.

' tovclose its normally opencontacts,

to take the pallet from hoist, when the I 'of the pile, when the pallet is lifted clear of the latch f members upon relativemovement between the hoists and, V the; pallet is to becompletely withdrawn from the auxiliary hoist, and when the armsfof the auxiliary hoist areto he swung out? after the withdrawal of the pallet.

, When the main hoist reaches a predetermined eleva-' tion, it actuates switch 216 (Fig; 'tIhEB llmlt SWitCh 216 is a' normally open switch a d, when actuated, closes its contacts to energize a relay coil 308* for actuating 'normally open contacts 308a, 308bj which are closed when the-relay coil is energized. The closing'of the I contacts 308a completes a circuit from Llc for energizing a relay 310. The contacts 308a are connected in series with a switch 312 (Fig; 2) mounted on'the auxiliary hoist frame 150 and engaged byone of the arms 154,

' 155 thereof and actuated tor-a closed position when the 7 arms are swung out, and opened as the arms are swung in. When the main hoist reaches a position where the pallet is to be taken therefrom, the arms of the auxiliary 'hoist are in their out position-and the limit switch 312 Y and an alarm 313 and alamp 314 through contacts 315a of flasher relay'coil 315 and its eontactsiilfib to energize lamp 222 in the control panel 221). The Lflasher 7 contacts 3150 make and break when thecoil and conpallet V V 1s t,o he 'initiallyywithdrawn toits position where the thin portion 205 thereof is disposed under the rear'edge the new pile has been properly positioned with its top immediatelyfbelow but not touching-the :pallet on the auxrharychoist, itisdesirable 'to operate both hoists nnder the controlof the pile height deteetor; or insyntacts are energized and the alarm andlamp will operate 7 intermittently; The relay 310 will keep the alarm 313 sounding and the lamp 314 flashing intermittently until the arms are swung in and the switch 312 is opened .to I drop out relay coil 310; After the arms have been swung in,'the relay coil 263 will operate to effect a continuous up movement of'the auxiliary hoist in the manner described above and the movement will be stopped when the hoist has taken the pallet from'the main hoist. As hereinbetore mentioned, when this'happens, thelclosing of the front switches 190 on therails 156,157 will effect After the pallet is taken by the auxiliary hoistglight 225 in the control panel 220 willlbeenergized to. indicate that the main hoist should be lowered The light 225 is energized by the energization of a relay coil 318 having contacts 318a connecting the light 225 to Llc. One'side of relay'coil 318,-is connected toLZ. and the other side to Llc by a connection which includes the normally open contacts 3081) actuated by the relay coil 308 and normally 7 open contacts 261d actuated by'the relay coil 261. As will 'be recalled, the taking of the pallet by the auxiliary-hoist chronism with each-other, until-the pileon the auxiliary hoist is depleted sufliciently to. where the piles on the main and auxiliary hoists are to be combined, The hoists may be synchronized so that the pile height detecting means will effect incremental operation of both by depressing the Synchronize push button 242. When the Synchronize? push button switch 242 is actuated, it opens its contacts 297 to de-energize the relay coil 295. It will be recalled that the relay coil 295'was energized bythe taking of the pallet by the auxiliary hoist to efiect energization of the solenoid 145 for lifting the pawl 84 clear of the ratchetwheel 90. When-the-circuitto the relay coil 295 is broken, the solenoid'145'is de-energized and the pawl 84 is then placed under the control of the pile height detector, as described above, and the pawl is operated to, raise the main hoist inincrements together with the auxiliary hoist. The actuation of'the relay 295 also vcloses its normally'open contacts 320 which complete a circuit from 'Llc through the now closed, normally-open contacts 261d-of the relay coil 261 to energize a relay coil 322 having normally open contacts 322a and 32211, The normallyopen contacts 322a'complete a holding circuit foriholding'therel-ay 322 energized'and are connected in'parallel withthe centac 320 of the -Synchronize switch 242' and the contacts 3221) complete a circuit for connecting the lamp 243 across L1, L2. The lamp 243. indicates'that the hoists have been synchronized and that the pile height detector will effect an incremental operation of both hoists when it detects a low pile level. i

When the pile onthe pallet on the auxiliary hoist is depleted to preferably approximately 1 /2 inches, the l'nnit switch 231 (Fig. 3) will be actuated by the auxiliary hoist. The closing of the "limit switch 231, completes a circuit forenergizing a relay coil 325 from Llthrough a circuit including the nowtcljosed contacts 26101015 the energizedw change-overv relay 261, normally closed conenergization :of the, relay coil 325 upon closing of the limit switch: 231 closes its normally open contacts 325a, 325k. YThe-normally open contacts 325a-are holding contacts which complete a holding -'circuit across the limit switch 231 and the contacts 3300 of relay coil 339, while the contacts 325]) are in a circuit forenergizing a relay coil 322 and when closed, connect one side of efiects' an energization of the changeover relay coil261 I and thelimit switch hen the main hoist 216, (Fig. 15) whichis actuated pallet therefrom effects reaches the position for taking the the energization of the relay coil 368 to efiect' the closing when the main hoist of its contacts 308b., Therefore, v takes the pallet, the reilaycoil 318 is energized 'to' close its contacts 318a to connect'the light 2 251across Llc and- L2 to indicate that the main hoist should he lowered and 7 a new pile brought into position and its1 contacts318b to energize flasher relay 315 and alarm 313 to Llc. As soon asIthe main hoistis lowered sufliciently to open the limit switcli216, the relay coil 308 and, in turn, the relay coil 318 will be de-energized to open the contacts 318a; extinguishing the light 225, flasher lamp 314. a V V V After the main hoist is lowered and a new pile brought into position thereon, the main hoist is elevated to position the topof the new pile immediately below the bottom ofjthe pallet on the auxiliary hoist, preparatory to combining the piles when theremnant pile, on. the auxiliary hoist is'depleted toa predeterm ned, lev l, After the alarm 313, and the 7 necting theLl side of the the relay coil 322 to Lie through the connection 327} including normally closed contacts 326a and the now closed contacts'261d'of change-over relay coil 261. The energization of the relay coil 332 closes contacts 332a and 3325. The contacts 332a are in-ai circuit for conalarm 313 and the lamp 314 to Llc; independently oftrthe flasher. contact 3151 and 1 when'closed, efiecta continuous energization of the alarm 313 and the lamp 314.J l t The contacts 332b of the relay coil 332, energized as just described, effect, when closed, "energization of the lamp 229 indicating that the pallet should be pulled and are connected in acircuit in series with normally closed contacts 326dof the relay coil 326;- Therefore, with the relay coil 326 de=energized, the normal condition of the relay, the energization of the 'relay 332b illuminates the pull pallet lamp 229.

When thepallet is pulled toia position where only the thin portion 295 thereof is disposed under, the rear edge of the remnant pile on the auxiliary hoist, the latch members 158 engage'andclose the limit switches 179, Before, however, th limit switches-170,170 are oyn- ,chronize switch 242 to break thecircuit for energizing 

